1. Field of the Invention
The present invention relates to a photographic printing apparatus, and more particularly to a photographic printing apparatus which has a mechanism for selecting a print size from a variety of print sizes, which can prevent an increase in the number of lens units used for printing due to an increase in the number of print sizes, and which can decrease the cost of lens units used for printing.
2. Description of the Related Art
With an increase in the number of print sizes and kinds of films, the frequency of changing the printing magnification during printing increases. Presently, a zoom lens is used to cope with frequent changes of magnification. However, since the printing magnification in actual printing varies over a considerable range from a very small magnification to a very large magnification, use of a single zoom lens is not suitable from the viewpoint of the quality of resulting pictures and the cost of the lens unit. Hence, a zoom lens which covers frequently used printing magnifications is used in combination with a variable focus lens covering other printing magnifications. Alternatively, two zoom lens which cover a lower-side magnification range and a higher-side magnification range, respectively, are selectively used.
In the above-described method in which a plurality of lens units are selectively used to cope With variation in the printing magnification, a large space is necessary to house the lens units. Therefore, lens units for printing must be made as compact as possible. However, such lens units actually become more complicated and larger due to a mechanism for automatic exposure.